Tencent cloud installs MySQL database

Database migration , Record how to install on the new server mysql, It is convenient for others as well as for yourself

1、 uninstall MariaDB

1、 see rpm -qa|grep mariadb
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2、 uninstall yum remove mariadb
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3、 Delete data directory  rm -rf /var/lib/mysql/* 
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4、 Delete profile rm -f /etc/my.cnf
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2. Download the corresponding package 
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1. Download and install MySQL Official  Yum Repository
     wget -i -c http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm
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2. download  MySQL  Repository configuration 
  yum -y install mysql57-community-release-el7-10.noarch.rpm
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3. download mysql service
   yum -y install mysql-community-server
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![image.png](https://p9-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/778909db22704ddbb57ef6e041228fd4~tplv-k3u1fbpfcp-watermark.awebp?)  This prompt indicates that the installation is successful 

 Installation did not succeed ,
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>  In step 3, an error may be reported during installation , as follows ：

![image.png](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/3783b61f9de64c97b121500e55f54df8~tplv-k3u1fbpfcp-watermark.awebp?)

** The solution is as follows :**

Execute first ： yum module disable mysql
Re execution ： yum install mysql-community-server
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>  Then you can execute successfully 

2. MySQL Database settings 
=============

1. see mysql The location of
   find / -name mysql
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![image.png](https://p1-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/ee768cd81b504b81894cbb5829327366~tplv-k3u1fbpfcp-watermark.awebp?)

>  The position shown in the figure is mysql The default installation location for 

2. start-up MySQL
systemctl start mysqld.service       
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  3. see MySQL state 
  systemctl status mysqld.service        
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```

![image.png](https://img-blog.csdnimg.cn/img_convert/ea6ade9a37f96e135e182595000b3deb.webp?x-oss-process=image/format,png)

```
 4. Get the initial password 
 grep "password" /var/log/mysqld.log   
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```

![image.png](https://img-blog.csdnimg.cn/img_convert/31f47655fe037166835e51992a8fb5a0.webp?x-oss-process=image/format,png)

```
5.  Enter the database to change the password 
mysql -u root -p xxxxx,
 And then execute ：
ALTER USER 'root'@'localhost' IDENTIFIED BY 'new password'
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```

 Here's the problem , If the new password is set too simply, an error will be reported ：

![](https://img-blog.csdnimg.cn/img_convert/5e7e647b44a9f4fa0b543ee2a083d02a.webp?x-oss-process=image/format,png)

 The reason is because MySQL There are specifications for password settings , Specifically validate\_password\_policy The value of ：

![](https://img-blog.csdnimg.cn/img_convert/a7f7dc130a86269d0e70d86f2c55e149.webp?x-oss-process=image/format,png)

** Change password rules **

```
1. set global validate_password_policy=0;

2. set global validate_password_length=1;
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```

   Reset the password 

```
  ALTER USER 'root'@'localhost' IDENTIFIED BY 'new password';  
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```

 Sign out and log back in 

mysql -u user name  -p password 

 The configuration is complete 

 Open the firewall 
=====

>  For firewalls , Everybody knows mysql The default port is 3306, If you can, you can change it yourself . Then open the port . Prevent malicious attacks from others 

```
1.  View firewall status 
 systemctl status firewalld
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```

![image.png](https://img-blog.csdnimg.cn/img_convert/c39b1b04adff2fec30530990a5f47bbc.webp?x-oss-process=image/format,png)

```
2.  Start the firewall 
systemctl start firewalld
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```

![image.png](https://img-blog.csdnimg.cn/img_convert/d9ced451af4ecb9617a7c88727d8219f.webp?x-oss-process=image/format,png)

```
3.  see mysql Whether the port of is open 
firewall-cmd --zone=public --query-port=3306/tcp
//    If you are open, the result is yes, It is no
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4. Open ports
   firewall-cmd --zone=public --add-port=3306/tcp --permanent
   // The console will output success
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5. service iptables restart 
firewall-cmd --reload
// Console output sucess, Just ok 了  
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```

 Login authorization for visualization tools 
==========

>  Do you think , After the above operations are completed , You can connect remotely , Not yet 

 Authorize remote clients , Otherwise, the connection fails , Permission validation failed .

（1）SSH Sign in root Administrator account 

（2） Sign in MySql

```
mysql -u root -p
Enter password: 
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```

（3） Execute the authorization order 

```
mysql> grant all privileges on *.* to [email protected]'localhost' identified by ' password ';
mysql> flush privileges;
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 or 

```
mysql> grant all privileges on *.* to [email protected]'%' identified by ' password ';
mysql> flush privileges;
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```

（4） Exit and try again 

```
mysql> quit
Bye
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```

（5） Log in again 

>  thereafter , The database installation is complete